/* SPDX-License-Identifier: BSD-3-Clause
 * Copyright(c) 2010-2015 Intel Corporation
 */

#include <inttypes.h>
#include <rte_cycles.h>
#include <rte_eal.h>
#include <rte_ethdev.h>
#include <rte_lcore.h>
#include <rte_mbuf.h>
#include <stdint.h>
#include <stdlib.h>

#define RX_RING_SIZE 1024
#define TX_RING_SIZE 1024

#define NUM_MBUFS 8191
#define MBUF_CACHE_SIZE 250
#define BURST_SIZE 32

/* basicfwd.c: Basic DPDK skeleton forwarding example. */

/*
 * Initializes a given port using global settings and with the RX buffers
 * coming from the mbuf_pool passed as a parameter.
 */

/* Main functional part of port initialization. 8< */
static inline int port_init(uint16_t port, struct rte_mempool *mbuf_pool) {
  struct rte_eth_conf port_conf;
  const uint16_t rx_rings = 1, tx_rings = 1;
  uint16_t nb_rxd = RX_RING_SIZE;
  uint16_t nb_txd = TX_RING_SIZE;
  int retval;
  uint16_t q;
  struct rte_eth_dev_info dev_info;
  struct rte_eth_txconf txconf;

  if (!rte_eth_dev_is_valid_port(port))
    return -1;

  memset(&port_conf, 0, sizeof(struct rte_eth_conf));

  retval = rte_eth_dev_info_get(port, &dev_info);
  if (retval != 0) {
    printf("Error during getting device (port %u) info: %s\n", port,
           strerror(-retval));
    return retval;
  }

  if (dev_info.tx_offload_capa & RTE_ETH_TX_OFFLOAD_MBUF_FAST_FREE)
    port_conf.txmode.offloads |= RTE_ETH_TX_OFFLOAD_MBUF_FAST_FREE;

  /* Configure the Ethernet device. */
  retval = rte_eth_dev_configure(port, rx_rings, tx_rings, &port_conf);
  if (retval != 0)
    return retval;

  retval = rte_eth_dev_adjust_nb_rx_tx_desc(port, &nb_rxd, &nb_txd);
  if (retval != 0)
    return retval;

  /* Allocate and set up 1 RX queue per Ethernet port. */
  for (q = 0; q < rx_rings; q++) {
    retval = rte_eth_rx_queue_setup(
        port, q, nb_rxd, rte_eth_dev_socket_id(port), NULL, mbuf_pool);
    if (retval < 0)
      return retval;
  }

  txconf = dev_info.default_txconf;
  txconf.offloads = port_conf.txmode.offloads;
  /* Allocate and set up 1 TX queue per Ethernet port. */
  for (q = 0; q < tx_rings; q++) {
    retval = rte_eth_tx_queue_setup(port, q, nb_txd,
                                    rte_eth_dev_socket_id(port), &txconf);
    if (retval < 0)
      return retval;
  }

  /* Starting Ethernet port. 8< */
  retval = rte_eth_dev_start(port);
  /* >8 End of starting of ethernet port. */
  if (retval < 0)
    return retval;

  /* Display the port MAC address. */
  struct rte_ether_addr addr;
  retval = rte_eth_macaddr_get(port, &addr);
  if (retval != 0)
    return retval;

  printf("Port %u MAC: %02" PRIx8 " %02" PRIx8 " %02" PRIx8 " %02" PRIx8
         " %02" PRIx8 " %02" PRIx8 "\n",
         port, RTE_ETHER_ADDR_BYTES(&addr));

  /* Enable RX in promiscuous mode for the Ethernet device. */
  retval = rte_eth_promiscuous_enable(port);
  /* End of setting RX port in promiscuous mode. */
  if (retval != 0)
    return retval;

  return 0;
}
/* >8 End of main functional part of port initialization. */

/*
 * The lcore main. This is the main thread that does the work, reading from
 * an input port and writing to an output port.
 */

/* Basic forwarding application lcore. 8< */
static __rte_noreturn void lcore_main(void) {
  uint16_t port;

  /*
   * Check that the port is on the same NUMA node as the polling thread
   * for best performance.
   */
  RTE_ETH_FOREACH_DEV(port)
  if (rte_eth_dev_socket_id(port) >= 0 &&
      rte_eth_dev_socket_id(port) != (int)rte_socket_id())
    printf("WARNING, port %u is on remote NUMA node to "
           "polling thread.\n\tPerformance will "
           "not be optimal.\n",
           port);

  printf("\nCore %u forwarding packets. [Ctrl+C to quit]\n", rte_lcore_id());

  /* Main work of application loop. 8< */
  for (;;) {
    /*
     * Receive packets on a port and forward them on the paired
     * port. The mapping is 0 -> 1, 1 -> 0, 2 -> 3, 3 -> 2, etc.
     */
    RTE_ETH_FOREACH_DEV(port) {

      /* Get burst of RX packets, from first port of pair. */
      struct rte_mbuf *bufs[BURST_SIZE];
      const uint16_t nb_rx = rte_eth_rx_burst(port, 0, bufs, BURST_SIZE);

      if (unlikely(nb_rx == 0))
        continue;

      /* Send burst of TX packets, to second port of pair. */
      const uint16_t nb_tx = rte_eth_tx_burst(port ^ 1, 0, bufs, nb_rx);

      /* Free any unsent packets. */
      if (unlikely(nb_tx < nb_rx)) {
        uint16_t buf;
        for (buf = nb_tx; buf < nb_rx; buf++)
          rte_pktmbuf_free(bufs[buf]);
      }
    }
  }
  /* >8 End of loop. */
}
/* >8 End Basic forwarding application lcore. */

/*
 * The main function, which does initialization and calls the per-lcore
 * functions.
 */
int main(int argc, char *argv[]) {
  struct rte_mempool *mbuf_pool;
  unsigned nb_ports;
  uint16_t portid;

  /* Initializion the Environment Abstraction Layer (EAL). 8< */
  int ret = rte_eal_init(argc, argv);
  if (ret < 0)
    rte_exit(EXIT_FAILURE, "Error with EAL initialization\n");
  /* >8 End of initialization the Environment Abstraction Layer (EAL). */

  argc -= ret;
  argv += ret;

  /* Check that there is an even number of ports to send/receive on. */
  nb_ports = rte_eth_dev_count_avail();
  if (nb_ports < 2 || (nb_ports & 1)) {
    fprintf(stderr, "port numbers: %u\n", nb_ports);
    rte_exit(EXIT_FAILURE, "Error: number of ports must be even\n");
  }

  /* Creates a new mempool in memory to hold the mbufs. */

  /* Allocates mempool to hold the mbufs. 8< */
  mbuf_pool = rte_pktmbuf_pool_create(
      "MBUF_POOL", NUM_MBUFS * nb_ports, MBUF_CACHE_SIZE, 0,
      RTE_MBUF_DEFAULT_BUF_SIZE, rte_socket_id());
  /* >8 End of allocating mempool to hold mbuf. */

  if (mbuf_pool == NULL)
    rte_exit(EXIT_FAILURE, "Cannot create mbuf pool\n");

  /* Initializing all ports. 8< */
  RTE_ETH_FOREACH_DEV(portid)
  if (port_init(portid, mbuf_pool) != 0)
    rte_exit(EXIT_FAILURE, "Cannot init port %" PRIu16 "\n", portid);
  /* >8 End of initializing all ports. */

  if (rte_lcore_count() > 1)
    printf("\nWARNING: Too many lcores enabled. Only 1 used.\n");

  /* Call lcore_main on the main core only. Called on single lcore. 8< */
  lcore_main();
  /* >8 End of called on single lcore. */

  /* clean up the EAL */
  rte_eal_cleanup();

  return 0;
}
